#include <cstdio>
#include <cstring>


/**
 * 
 * 字符串操作
 */
int main() {
    char words[110]{};

    scanf("%s", words);


    int leftPointer = 0;
    int rightPointer = strlen(words) - 1;

    bool flag = true;
    while (leftPointer < rightPointer) {
        if (words[leftPointer] != words[rightPointer]) {
            flag = false;
            break;
        }
        leftPointer++;
        rightPointer--;
    }

    if (flag) {
        printf("yes\n");
    }
    else {
        printf("no\n");
    }

    return 0;
}